Understanding Sacroiliitis and Sacroiliac Dysfunction

Sep 24

When patients describe deep pain in the lower back, buttocks, or hips, one often overlooked source is the sacroiliac joint. Problems in this joint can lead to conditions called sacroiliitis or sacroiliac (SI) dysfunction. While the names sound similar, understanding the difference can help you make sense of your pain and your treatment options.

What Is the Sacroiliac Joint?

The sacroiliac joint connects the sacrum (the triangular bone at the base of your spine) with the iliac bones of the pelvis. It acts as a shock absorber, transferring weight and motion between your upper body and legs.

Even though it doesn’t move very much, when it becomes irritated, inflamed, or unstable, it can cause significant pain.

Sacroiliitis vs. Sacroiliac Dysfunction

Sacroiliitis means inflammation of the sacroiliac joint. This can be due to arthritis, autoimmune conditions, trauma, or infection.
Sacroiliac dysfunction refers to abnormal movement in the joint—either too much (hypermobility) or too little (hypomobility). This can result from injury, pregnancy, prior spine surgery, or degenerative changes.

Common Symptoms

Pain from sacroiliitis or SI dysfunction can mimic other spine and hip problems. Symptoms often include:

Pain in the buttocks, lower back, or hips (sometimes on just one side).
Pain that radiates to the thigh or groin, but rarely past the knee.
Discomfort or pain when changing positions - standing up from sitting, sitting down from standing, climbing stairs, lying on one side, getting up off the toilet
Stiffness in the morning or after long periods of sitting.

Causes and Risk Factors

Arthritis (such as osteoarthritis or ankylosing spondylitis).
Pregnancy (due to hormonal changes and increased joint laxity).
Injury or trauma (falls, car accidents, sports injuries).
Spinal surgery or fusion (which can put more stress on the SI joint).
Infections (though less common).

Diagnosis

Because SI joint pain can mimic disc problems or hip arthritis, diagnosis can be tricky. A specialist may use:

Physical exam maneuvers that stress the joint.
Imaging (X-ray, CT, or MRI) to look for inflammation or degeneration, although this is the LEAST helpful but helps rule out other causes besides SI joint issues.
Diagnostic injections—numbing the joint temporarily to confirm if it’s the pain source.

Treatment Options

The good news is that SI joint pain is treatable. Options include:

Activity modification and physical therapy – improving posture, flexibility, and core strength.
Medications – anti-inflammatories or pain relievers.
Injections – steroid injections can calm inflammation.
Minimally invasive SI joint fusion – considered when pain is severe and persistent, this stabilizes the joint with small implants or screws.

When to Seek Help

If your pain is persistent, interferes with daily activities, or doesn’t improve with rest and over-the-counter medications, it’s important to see a spine or joint specialist. Identifying the true source of pain is the key to lasting relief.

Takeaway

Sacroiliitis and sacroiliac dysfunction are common but often overlooked causes of low back and buttock pain. With the right diagnosis and treatment, most patients can find significant relief and return to their normal activities.

Naples Office: (239) 649-1662
Fort Myers Office: (239) 437-1121
or click the “Contact” tab above to get scheduled.